Hylobates lar

Short phrases consisting of simple hoots, various
more complex hoots, and specific quaver notes produced by tremulous opening and semi-closing
of the mouth during long hoots. Short phrases produced by males and females, but
quaver notes are typically produced by males only. Female great call very similar
to that of H. agilis, but usually longer, with longer notes, and with more
pronounced first climax, and fewer notes dedicated to second climax than in H.
agilis. Male produces coda. Male solo song bouts and duet song bouts.

Duet song, adult pair "182/1" and "Sally",
Paignton Zoo, U.K., 21 Oct. 1988.
The two infant offspring of this pair do not contribute to the song bout.

Isolated solo great call of widdowed adult female,
Zoo Al Maglio, Switzerland, 23 Nov. 1987.
The adult daughter of this female is also kept in the same cage, but does not contribute
to the great calls of her mother. It's raining during this tape-recording.